Automatically Analyzing and Modifying a Graphical Program

ABSTRACT

A system and method for programmatically analyzing and modifying a graphical program. The graphical program may be stored in a memory. The graphical program may then be programmatically analyzed. In various embodiments, the graphical program may be a graphical program that performs any function for any application, and the graphical program may be analyzed to determine any information or characteristics regarding the graphical program. One or more suggested modifications to the graphical program may be displayed based on the programmatic analysis performed on the graphical program. The user may be able to select which of the suggested modifications to automatically apply to the graphical program. The graphical program may then be programmatically modified to implement the one or more suggested modifications selected by the user.

CONTINUATION DATA

This application is a continuation of U.S. application Ser. No. 10/303,525 titled “Programmatically Analyzing and Modifying a Graphical Program” filed Nov. 25, 2002, whose inventors are Joel Sumner, Daniel Hedges, Phil Joffrain and Darren Nattinger, which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to the fields of computer software and graphical programming. More particularly, the invention relates to a system and method for programmatically analyzing a graphical program, and possibly programmatically modifying the graphical program in response to the analysis performed

DESCRIPTION OF THE RELATED ART

Traditionally, high level text-based programming languages have been used by programmers in writing application programs. Many different high level programming languages exist, including BASIC, C, Java, FORTRAN, Pascal, COBOL, ADA, APL, etc. Programs written in these high level languages are translated to the machine language level by translators known as compilers or interpreters. The high level programming languages in this level, as well as the assembly language level, are referred to herein as text-based programming environments.

Increasingly, computers are required to be used and programmed by those who are not highly trained in computer programming techniques. When traditional text-based programming environments are used, the user's programming skills and ability to interact with the computer system often become a limiting factor in the achievement of optimal utilization of the computer system.

There are numerous subtle complexities which a user must master before he can efficiently program a computer system in a text-based environment. The task of programming a computer system to model or implement a process often is further complicated by the fact that a sequence of mathematical formulas, steps or other procedures customarily used to conceptually model a process often does not closely correspond to the traditional text-based programming techniques used to program a computer system to model such a process. In other words, the requirement that a user program in a text-based programming environment places a level of abstraction between the user's conceptualization of the solution and the implementation of a method that accomplishes this solution in a computer program. Thus, a user often must substantially master different skills in order to both conceptualize a problem or process and then to program a computer to implement a solution to the problem or process. Since a user often is not fully proficient in techniques for programming a computer system in a text-based environment to implement his solution, the efficiency with which the computer system can be utilized often is reduced.

Examples of fields in which computer systems are employed to interact with physical systems are the fields of instrumentation, process control, industrial automation, and simulation. Computer measurement and control of devices such as instruments or industrial automation hardware has become increasingly desirable in view of the increasing complexity and variety of instruments and devices available for use. However, due to the wide variety of possible testing and control situations and environments, and also the wide array of instruments or devices available, it is often necessary for a user to develop a custom program to control a desired system.

As discussed above, computer programs used to control such systems traditionally had to be written in text-based programming languages such as, for example, assembly language, C, FORTRAN, BASIC, etc. Traditional users of these systems, however, often were not highly trained in programming techniques and, in addition, text-based programming languages were not sufficiently intuitive to allow users to use these languages without training. Therefore, implementation of such systems frequently required the involvement of a programmer to write software for control and analysis of instrumentation or industrial automation data. Thus, development and maintenance of the software elements in these systems often proved to be difficult.

U.S. Pat. Nos. 4,901,221; 4,914,568; 5,291,587; 5,301,301; and 5,301,336; among others, to Kodosky et al disclose a graphical system and method for modeling a process, i.e., a graphical programming environment which enables a user to easily and intuitively model a process. The graphical programming environment disclosed in Kodosky et al can be considered a higher and more intuitive way in which to interact with a computer. A graphically based programming environment can be represented at a level above text-based high level programming languages such as C, Basic, Java, etc.

The method disclosed in Kodosky et al allows a user to construct a diagram using a block diagram editor. The block diagram may include a plurality of interconnected icons such that the diagram created graphically displays a procedure or method for accomplishing a certain result, such as manipulating one or more input variables and/or producing one or more output variables. In response to the user constructing a diagram or graphical program using the block diagram editor, data structures and/or program instructions may be automatically constructed which characterize an execution procedure that corresponds to the displayed procedure. The graphical program may be compiled or interpreted by a computer.

Therefore, Kodosky et al teaches a graphical programming environment wherein a user places or manipulates icons and interconnects or “wires up” the icons in a block diagram using a block diagram editor to create a graphical “program.” A graphical program for performing an instrumentation, measurement or automation function, such as measuring a Unit Under Test (UUT) or device, controlling or modeling instruments, controlling or measuring a system or process, or for modeling or simulating devices, may be referred to as a virtual instrument (VI). Thus, a user can create a computer program solely by using a graphically based programming environment. This graphically based programming environment may be used for creating virtual instrumentation systems, modeling processes, control, simulation, and numerical analysis, as well as for any type of general programming.

A graphical program may have a graphical user interface. For example, in creating a graphical program, a user may create a front panel or user interface panel. The graphical user interface may include various graphical user interface elements or front panel objects, such as user interface controls and/or indicators that represent or display the respective input and output used or produced by the graphical program or VI, and may include other icons which represent devices being controlled. The graphical user interface may be comprised in a single window of user interface elements, or may comprise a plurality of individual windows each having one or more user interface elements, wherein the individual windows may optionally be tiled together. When the user interface controls and indicators are created, corresponding icons or terminals may be automatically created in the block diagram. Alternatively, the user can place terminal icons in the block diagram which may cause the display of corresponding user interface elements in the graphical user interface, either at edit time or later at run time. As another example, the graphical user interface panel may comprise user interface elements or front panel objects, e.g., the GUI, embedded in the block diagram. Further, the user interface may be characterized as a “front panel” where the user may interactively control or manipulate the input being provided to the graphical program and view the resulting output during program execution.

During creation of the block diagram portion of the graphical program, the user may select various function nodes or icons that accomplish his desired result and connect the function nodes together. For example, the function nodes may be connected in one or more of a data flow, control flow, and/or execution flow format. The function nodes may also be connected in a “signal flow” format, which is a subset of data flow. The function nodes may be connected between the terminals of the various user interface elements, e.g., between the respective controls and indicators. Thus the user may create or assemble a graphical program, referred to as a block diagram, graphically representing the desired process. The assembled graphical program may be represented in the memory of the computer system as data structures and/or program instructions. The assembled graphical program, i.e., these data structures, may then be compiled or interpreted to produce machine language that accomplishes the desired method or process as shown in the block diagram.

Input data to a graphical program may be received from any of various sources, such as from a device, unit under test, a process being measured or controlled, another computer program, or from a file. Also, a user may input data to a graphical program or virtual instrument using a graphical user interface, e.g., a front panel as described above. The input data may propagate through the block diagram or graphical program and appear as changes on the output indicators. In an instrumentation application, the front panel can be analogized to the front panel of an instrument. In an industrial automation application the front panel can be analogized to the MMI (Man Machine Interface) of a device. The user may adjust the controls on the front panel to affect the input and view the output on the respective indicators. Alternatively, the user interface may be used merely to view the input and output, or just the output, and the input may not be interactively manipulable by the user during program execution.

Thus, graphical programming has become a powerful tool available to programmers. Graphical programming environments such as the National Instruments LabVIEW product have become very popular. Tools such as LabVIEW have greatly increased the productivity of programmers, and increasing numbers of programmers are using graphical programming environments to develop their software applications. In particular, graphical programming tools are being used for test and measurement, data acquisition, process control, man machine interface (MMI), supervisory control and data acquisition (SCADA) applications, simulation, image processing/machine vision applications, and motion control, among others.

Users typically create graphical programs manually, e.g., using a block diagram editor as described above. In prior systems, users have generally been responsible for manually making any changes required to a graphical program. However, in many instances it would be desirable to assist users by automatically analyzing a graphical program for various purposes. It may also be desirable to automatically modify the graphical program based on the analysis. As one example, it may be desirable to provide a system and method to automatically analyze a graphical program to determine factors which limit the program's performance and to automatically modify the graphical program to improve its performance. As other examples, it may be desirable to automatically analyze and modify a graphical program to correct errors in the graphical program, to update the graphical program, to change the functionality of the graphical program, to change the style of the graphical program's graphical user interface, etc.

SUMMARY

One embodiment of the present invention comprises a system and method for programmatically analyzing a graphical program. The system and method may then suggest modifications to the graphical program based on the programmatic analysis. The system and method may also (or instead) operate to programmatically modify the graphical program based on the analysis performed.

In various embodiments it may be desirable to programmatically, i.e., automatically, analyze (and possibly programmatically modify) the graphical program for any of various reasons. As one example, it may be desirable to programmatically analyze a graphical program to determine factors which limit the program's performance and to suggest changes to (or programmatically modify) the graphical program to improve its performance. As other examples, it may be desirable to programmatically analyze a graphical program and suggest changes to (or programmatically modify) the graphical program to correct errors in the graphical program, to update the graphical program, to change the functionality of the graphical program, to change the style of the graphical program's graphical user interface, etc. In various embodiments, the graphical program that is programmatically analyzed (and possibly programmatically modified) may be any type of graphical program and may perform any function.

According to one embodiment, a user may first create the graphical program. Creating the graphical program may include creating a block diagram for the graphical program. Creating the graphical program may also include creating a graphical user interface for the graphical program. In another embodiment, the graphical program may be programmatically generated rather than being manually created by a user. The graphical program may be stored in a memory.

The graphical program may then be programmatically analyzed. In various embodiments, the graphical program may be a graphical program that performs any function for any application, and the graphical program may be analyzed to determine any information or characteristics regarding the graphical program. Several exemplary graphical program analyses are discussed below.

Programmatically analyzing the graphical program may include any technique or method implemented by a program that inspects or examines the graphical program. For example, programmatically analyzing the graphical program may include analyzing one or more data structures and/or program instructions representing the graphical program in the memory, e.g., to determine graphical program elements (e.g., nodes, programmatic structures such as loops or case structures, user interface elements, connections, comments, etc.) present in the graphical program and/or to determine a relationship among these graphical program elements.

In one embodiment, the user may select a desired criteria for the programmatic analysis. For example, the programmatic analysis may be performed to suggest modifications, or programmatically make modifications, to 1) improve performance of the graphical program, 2) correct errors in the graphical program, 3) update the graphical program, 4) reduce the footprint of the graphical program, 5) change the functionality of the graphical program to perform a user specified function, 6) modify the graphical program for a specific target (e.g., an embedded target or an FPGA) and/or 7) change the style of the graphical program's block diagram and/or graphical user interface.

In one embodiment, one or more suggested modifications to the graphical program may be displayed. The one or more suggested modifications may be based on the programmatic analysis performed on the graphical program. The suggested modifications which are displayed may depend on the purpose or reason for analyzing the graphical program. As one example, in one embodiment, the goal may be to increase performance of the graphical program. Thus, the graphical program may be programmatically analyzed to determine information indicative of the graphical program's performance, and one or more suggestions for increasing the performance may be displayed based on this information.

In one embodiment, the suggested modifications are displayed as proposed modifications to the graphical program, wherein the proposed modifications are highlighted in some way. For example, the proposed modifications may appear as one or more new nodes and/or wires in the graphical program, one or nodes and/or wires proposed for deletion in the graphical program, and/or one or more proposed substitutions of nodes and/or wires, among other possible proposed modifications.

In one embodiment, the suggested modifications may be not only displayed, but may also be automatically, i.e., programmatically, applied to the graphical program. In one embodiment, the user may be able to select which of the suggested modifications to automatically apply to the graphical program. User input selecting one or more of the suggested modifications to apply to the graphical program may be received. Various techniques may be used to prompt the user for this user input. For example, in one embodiment, the user may simply click a button or perform another action to request all the suggested modifications to be applied. In another embodiment, the user may be able to select a subset of the modifications to apply or may be prompted for a decision on whether to apply each modification one at a time.

In an alternative embodiment, the suggested modifications may be not displayed and/or the user may not be prompted to select which modifications to apply. Instead, the method may simply programmatically analyze the graphical program and programmatically modify the graphical program based on the analysis without interacting with the user as described above. The user may be able to select a “graphical program differencing function” to compare the old and new graphical programs and display the changes that have been made.

The graphical program may be programmatically modified to implement the one or more suggested modifications selected by the user. The graphical program may be programmatically modified with little or no input received during the modification process. In one embodiment, the method may include displaying a series of user interface panels or screens to guide the user through the process of modifying the graphical program or to allow the user to specify options affecting the modifications made to the graphical program.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when the following detailed description of the preferred embodiment is considered in conjunction with the following drawings, in which:

FIG. 1 illustrates a computer system operable to programmatically analyze a graphical program and programmatically modify the graphical program based on the analysis;

FIG. 1A illustrates an exemplary networked computer system;

FIG. 2A illustrates an exemplary instrumentation control system;

FIG. 2B illustrates an exemplary industrial automation system;

FIG. 3 is an exemplary block diagram of a computer system shown in FIGS. 1, 1A, 2A and/or 2B;

FIG. 4 is a flowchart diagram illustrating one embodiment of a method for programmatically analyzing and modifying a graphical program; and

FIGS. 5-8 illustrate exemplary graphical programs related to an application in which a time-critical graphical program is programmatically analyzed and modified to improve its performance by removing user interface functionality from the time-critical graphical program.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE EMBODIMENTS Incorporation by Reference

The following references are hereby incorporated by reference in their entirety as though fully and completely set forth herein:

U.S. application Ser. No. 10/303,525 titled “Programmatically Analyzing and Modifying a Graphical Program” filed Nov. 25, 2002.

U.S. Pat. No. 4,914,568 titled “Graphical System for Modeling a Process and Associated Method,” issued on Apr. 3, 1990.

U.S. Pat. No. 5,481,741 titled “Method and Apparatus for Providing Attribute Nodes in a Graphical Data Flow Environment” issued on Jan. 2, 1996.

U.S. Pat. No. 6,173,438 titled “Embedded Graphical Programming System” issued on Jan. 9, 2001.

U.S. Pat. No. 6,219,628 titled “System and Method for Configuring an Instrument to Perform Measurement Functions Utilizing Conversion of Graphical Programs into Hardware Implementations,” issued on Apr. 17, 2001.

U.S. Pat. No. 6,138,270 titled “System, Method and Memory Medium for Detecting Differences Between Graphical Programs” issued on Oct. 24, 2000.

U.S. patent application Ser. No. 09/617,600 titled “Graphical Programming System with Distributed Block Diagram Execution and Front Panel Display,” filed Jun. 13, 2000.

U.S. patent application Ser. No. 09/518,492 titled “System and Method for Programmatically Creating a Graphical Program,” filed Mar. 3, 2000.

U.S. patent application Ser. No. 09/745,023 titled “System and Method for Programmatically Generating a Graphical Program in Response to Program Information,” filed Dec. 20, 2000.

U.S. patent application Ser. No. 10/198,213 titled “Wizard for Programmatically Analyzing and Modifying Time-Critical Graphical Programs,” filed Jul. 18, 2002.

U.S. patent application Ser. No. 10/177,553 titled “Target Device-Specific Syntax and Semantic Analysis For a Graphical Program,” filed Jun. 21, 2002.

The LabVIEW graphical programming manuals, including the “G Programming Reference Manual”, available from National Instruments Corporation, are also hereby incorporated by reference in their entirety.

FIG. 1—Computer System

FIG. 1 illustrates a computer system 82 operable to programmatically analyze a graphical program and optionally programmatically modify the graphical program based on the analysis. The computer system 82 may programmatically, i.e., automatically, analyze and modify the graphical program for any of various reasons. As one example, it may be desirable to programmatically analyze a graphical program to determine factors which limit the program's performance and to programmatically modify the graphical program to improve its performance. As other examples, it may be desirable to programmatically analyze and modify a graphical program to correct errors in the graphical program, to update the graphical program, to change the functionality of the graphical program, to change the style of the graphical program's graphical user interface, etc. In various embodiments, the graphical program that is programmatically analyzed and modified may be any type of graphical program and may perform any function.

As used herein, the term “programmatically” is intended to mean that the associated operation is performed by a program (as opposed to being performed manually by a user), such as a program executing in a computer or a program executing in a programmable hardware device such as an FPGA.

In the present application, the term “graphical program” or “block diagram” is intended to include a program comprising graphical source code, e.g., two or more interconnected nodes or icons, wherein the interconnected nodes or icons may visually indicate the functionality of the program. The nodes may be connected in one or more of a data flow, control flow, and/or execution flow format. The nodes may also be connected in a “signal flow” format, which is a subset of data flow. Thus the terms “graphical program” or “block diagram” are each intended to include a program comprising a plurality of interconnected nodes or icons which visually indicate the functionality of the program. A data flow graphical program or data flow diagram refers to a graphical program or block diagram wherein the interconnections between nodes or blocks indicate that data produced by one block is used by another block.

A graphical program may also comprise a user interface or front panel. The user interface portion may be contained in the block diagram or may be contained in one or more separate panels or windows. The user interface of a graphical program may include various graphical user interface elements or front panel objects, such as user interface controls and/or indicators, that represent or display the respective input and/or output used or produced by the graphical program or VI, and may include other icons which represent devices being controlled. The user interface may be comprised in a single window of user interface elements, or may comprise a plurality of individual windows each having one or more user interface elements, wherein the individual windows may optionally be tiled together. As another example, the user interface may comprise user interface or front panel objects, e.g., the GUI, embedded in the block diagram. The user interface of a graphical program may display only output, only input, or both input and output. Further, the user interface may be characterized as a “front panel” where the user may interactively control or manipulate the input being provided to the graphical program and view the resulting output during program execution.

Examples of graphical programming development environments that may be used to create graphical programs include LabVIEW, DasyLab, and DiaDem from National Instruments, VEE from Agilent, WiT from Coreco, Vision Program Manager from PPT Vision, SoftWIRE from Measurement Computing, Simulink from The MathWorks, Sanscript from Northwoods Software, Khoros from Khoral Research, SnapMaster from HEM Data, VisSim from Visual Solutions, ObjectBench by SES (Scientific and Engineering Software), and VisiDAQ from Advantech, among others.

Referring again to FIG. 1, the computer system 82 may be any type of computer system, including a personal computer system, mainframe computer system, workstation, network appliance, Internet appliance, personal digital assistant (PDA), television system, or other device. In general, the term “computer system” can be broadly defined to encompass any device having at least one processor that executes instructions from a memory medium.

The computer system 82 may include a memory medium(s) on which one or more computer programs or software components according to one embodiment of the present invention may be stored. For example, the memory medium may store one or more graphical programs which are to be analyzed/modified according to the methods described herein. Also, the memory medium may store a program operable to programmatically analyze and modify the graphical program(s). The memory medium may also store operating system software, as well as other software for operation of the computer system.

The term “memory medium” is intended to include an installation medium, e.g., a CD-ROM, floppy disks 104, or tape device; a computer system memory or random access memory such as DRAM, SRAM, EDO RAM, Rambus RAM, etc.; or a non-volatile memory such as a magnetic media, e.g., a hard drive, or optical storage. The memory medium may comprise other types of memory as well, or combinations thereof. In addition, the memory medium may be located in a first computer in which the programs are executed, or may be located in a second different computer which connects to the first computer over a network, such as the Internet. In the latter instance, the second computer may provide program instructions to the first computer for execution.

Various embodiments further include receiving or storing instructions and/or data implemented in accordance with the present description upon a carrier medium. Suitable carrier media include a memory medium as described above, as well as signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as networks and/or a wireless link.

FIG. 1A—System Environment

FIG. 1A illustrates an exemplary system including the first computer system 82 of FIG. 1. In this example, the first computer system 82 is coupled to a second computer system 90 over a network. The computer system 82 may be coupled through a network 84 (or a computer bus) to the second computer system 90. The computer systems 82 and 90 may each be any of various types, as desired. Also, the network 84 can be any of various types, including a LAN (local area network), WAN (wide area network), the Internet, or an Intranet, among others.

The first and second computer systems 82 and 90 may comprise devices that form at least a portion of a system, such as a distributed system. In one embodiment, the first computer system 82 may comprise part of the system, and the second computer system 90 may act as a remote computer server providing various services to the first computer system 82. In one embodiment, the second computer system 90 may be operable to programmatically analyze and/or modify a graphical program stored on the first computer system 82, or vice versa.

Additional computer systems (not shown) may also couple to the first and/or second computer systems 82 and 90. Various other devices may connect or couple to one or more of the computer systems 82 and 90, or to other computer systems in the system. For example, any one or more of the devices shown in FIGS. 2A and 2B may couple to one or both of the computer systems 82 and 90. In addition, the system may comprise a single computer system, such as computer system 82, coupled to one or more other devices.

FIGS. 2A and 2B—Instrumentation and Industrial Automation Systems

The following describes embodiments of the present invention involved with performing test and/or measurement functions and/or controlling and/or modeling instrumentation or industrial automation hardware. However, it is noted that the present invention can be used for a plethora of applications and are not limited to instrumentation or industrial automation applications. In other words, the following description is exemplary only, and the present invention may be used in any of various types of systems. Thus, the system and method of the present invention is operable to be used in any of various types of applications, including the simulation, modeling and/or control of various types of devices, as well as general purpose software applications such as word processing, spreadsheets, network control, games, etc.

FIG. 2A illustrates an exemplary instrumentation control system 100. The system 100 comprises a host computer 82 which connects to one or more instruments. The host computer 82 may comprise a CPU, a display screen, memory, and one or more input devices such as a mouse or keyboard as shown. The computer 82 may operate with the one or more instruments to analyze, measure or control a unit under test (UUT) or process 150.

In one embodiment, a graphical program that is programmatically analyzed and modified as described herein may be a program that interacts with or controls one or more of the instruments shown in FIG. 2A. In another embodiment, the graphical program (or a portion of the graphical program) may be executed on one or more of the instruments. For example, in one embodiment, one or more of the instruments may include an embedded CPU and memory and may execute a real time kernel and a graphical program execution engine to enable execution of graphical programs in a real-time or deterministic manner. For example, one or more of the GPIB card 122, the DAQ card 114, or the VXI card may comprise an embedded system. Alternatively, or in addition, one or more of the GPIB instrument 112, the VXI instrument 116, or the serial instrument may comprise an embedded system.

The one or more instruments may include a GPIB instrument 112 and associated GPIB interface card 122, a data acquisition board 114 and associated signal conditioning circuitry 124, a VXI instrument 116, a PXI instrument 118, a video device or camera 132 and associated image acquisition (or machine vision) card 134, a motion control device 136 and associated motion control interface card 138, and/or one or more computer based instrument cards 142, among other types of devices.

The GPIB instrument 112 may be coupled to the computer 82 via the GPIB interface card 122 provided by the computer 82. In a similar manner, the video device 132 may be coupled to the computer 82 via the image acquisition card 134, and the motion control device 136 may be coupled to the computer 82 through the motion control interface card 138. The data acquisition board 114 may be coupled to the computer 82, and may interface through signal conditioning circuitry 124 to the UUT. The signal conditioning circuitry 124 may comprise an SCXI (Signal Conditioning eXtensions for Instrumentation) chassis comprising one or more SCXI modules 126.

The GPIB card 122, the image acquisition card 134, the motion control interface card 138, and the DAQ card 114 are typically plugged in to an I/O slot in the computer 82, such as a PCI bus slot, a PC Card slot, or an ISA, EISA or MicroChannel bus slot provided by the computer 82. However, these cards 122, 134, 138 and 114 are shown external to computer 82 for illustrative purposes. These devices may also be connected to the computer 82 through a serial bus or through other means.

The VXI chassis or instrument 116 may be coupled to the computer 82 via a VXI bus, MXI bus, or other serial or parallel bus provided by the computer 82. The computer 82 may include VXI interface logic, such as a VXI, MXI or GPIB interface card (not shown), which interfaces to the VXI chassis 116. The PXI chassis or instrument may be coupled to the computer 82 through the computer's PCI bus.

A serial instrument (not shown) may also be coupled to the computer 82 through a serial port, such as an RS-232 port, USB (Universal Serial bus) or IEEE 1394 or 1394.2 bus, provided by the computer 82. In typical instrumentation control systems an instrument will not be present of each interface type, and in fact many systems may only have one or more instruments of a single interface type, such as only GPIB instruments.

The instruments may be coupled to a unit under test (UUT) or process 150, or may be coupled to receive field signals, typically generated by transducers. The system 100 may be used in a data acquisition and control application, in a test and measurement application, an image processing or machine vision application, a process control application, a man-machine interface application, a simulation application, or a hardware-in-the-loop validation application.

FIG. 2B illustrates an exemplary industrial automation system 160. The industrial automation system 160 is similar to the instrumentation or test and measurement system 100 shown in FIG. 2A. Elements which are similar or identical to elements in FIG. 2A have the same reference numerals for convenience. The system 160 may comprise a computer 82 which connects to one or more devices or instruments. The computer 82 may comprise a CPU, a display screen, memory, and one or more input devices such as a mouse or keyboard as shown. The computer 82 may operate with the one or more devices to a process or device 150 to perform an automation function, such as MMI (Man Machine Interface), SCADA (Supervisory Control and Data Acquisition), portable or distributed data acquisition, process control, advanced analysis, or other control.

In one embodiment, a graphical program that is programmatically analyzed and modified as described herein may be a program that interacts with or controls one or more of the devices shown in FIG. 2B. In another embodiment, the graphical program (or a portion of the graphical program) may be executed on one or more of the devices, similarly as described above with reference to FIG. 2A.

The one or more devices may include a data acquisition board 114 and associated signal conditioning circuitry 124, a PXI instrument 118, a video device 132 and associated image acquisition card 134, a motion control device 136 and associated motion control interface card 138, a fieldbus device 170 and associated fieldbus interface card 172, a PLC (Programmable Logic Controller) 176, a serial instrument 182 and associated serial interface card 184, or a distributed data acquisition system, such as the Fieldpoint system available from National Instruments, among other types of devices.

The DAQ card 114, the PXI chassis 118, the video device 132, and the image acquisition card 134 may be connected to the computer 82 as described above. The serial instrument 182 may be coupled to the computer 82 through a serial interface card 184, or through a serial port, such as an RS-232 port, provided by the computer 82. The PLC 176 may couple to the computer 82 through a serial port, Ethernet port, or a proprietary interface. The fieldbus interface card 172 may be comprised in the computer 82 and may interface through a fieldbus network to one or more fieldbus devices. Each of the DAQ card 114, the serial card 184, the fieldbus card 172, the image acquisition card 134, and the motion control card 138 are typically plugged in to an I/O slot in the computer 82 as described above. However, these cards 114, 184, 172, 134, and 138 are shown external to computer 82 for illustrative purposes. In typical industrial automation systems a device will not be present of each interface type, and in fact many systems may only have one or more devices of a single interface type, such as only PLCs. The devices may be coupled to the device or process 150.

As used herein, the term “instrument” is intended to include any of the devices that are adapted to be connected to a computer system as shown in FIGS. 2A and 2B, traditional “stand-alone” instruments, as well as other types of measurement and control devices. The term “measurement function” may include any type of data acquisition, measurement or control function, such as that implemented by the instruments shown in FIGS. 2A and 2B. For example, the term “measurement function” includes acquisition and/or processing of an image. In one embodiment, a graphical program that undergoes programmatic analysis and modification as described herein may implement a measurement function. As one example, a time-critical graphical program may be used to acquire measurement data using a hardware input function. Graphical programs which perform data acquisition, analysis and/or presentation, e.g., for measurement, instrumentation control, industrial automation, or simulation, such as in the applications shown in FIGS. 2A and 2B, may be referred to as virtual instruments.

FIG. 3—Computer System Block Diagram

FIG. 3 is a block diagram representing one embodiment of the computer system 82 and/or 90 illustrated in FIGS. 1, 1A, 2A and/or 2B. It is noted that any type of computer system configuration or architecture can be used as desired, and FIG. 3 illustrates a representative PC embodiment. It is also noted that the computer system may be a general purpose computer system, a computer implemented on a VXI card installed in a VXI chassis, a computer implemented on a PXI card installed in a PXI chassis, or other types of embodiments. Elements of a computer not necessary to understand the present description have been omitted for simplicity.

The computer may include at least one central processing unit or CPU 160 which is coupled to a processor or host bus 162. The CPU 160 may be any of various types, including an x86 processor, e.g., a Pentium class, a PowerPC processor, a CPU from the SPARC family of RISC processors, as well as others. Main memory 166 is coupled to the host bus 162 by means of memory controller 164. In one embodiment, the main memory 166 may store a graphical program to be programmatically analyzed and/or modified. In one embodiment, the main memory may also, or may alternatively, store software operable to programmatically analyze and modify a graphical program, as described above with reference to FIG. 1. The main memory may also store operating system software, as well as other software for operation of the computer system.

The host bus 162 may be coupled to an expansion or input/output bus 170 by means of a bus controller 168 or bus bridge logic. The expansion bus 170 may be the PCI (Peripheral Component Interconnect) expansion bus, although other bus types can be used. The expansion bus 170 includes slots for various devices such as a data acquisition board 114 and a GPIB interface card 122 which provides a GPIB bus interface to a GPIB instrument. The computer 82 further comprises a video display subsystem 180 and hard drive 182 coupled to the expansion bus 170.

In one embodiment, one or more of the interface cards or devices coupled to the expansion bus, such as the DAQ card 114, the GPIB interface card 122, the GPIB instrument 112, or a VXI or MXI bus card 186 may comprise an embedded system including an embedded CPU and embedded memory. In this embodiment, the graphical program that is programmatically analyzed and modified may be executed in the embedded system. Also, the graphical program may be programmatically analyzed/modified first and may then be transferred to the embedded system, or the graphical program may be programmatically analyzed/modified while it is stored in the embedded system. Similarly, in one embodiment one or more of the interface cards or devices coupled to the expansion bus may include configurable logic, such as an FPGA, on which the graphical program is executed.

FIG. 4—Method for Programmatically Analyzing and Modifying a Graphical Program

FIG. 4 is a flowchart diagram illustrating one embodiment of a method for programmatically analyzing and modifying a graphical program. It is noted that FIG. 4 illustrates a representative embodiment, and alternative embodiments are contemplated.

In 301, a user may create the graphical program. In various embodiments, the graphical program may be created using any graphical programming development environment. Examples of graphical programming development environments for creating graphical programs were provided above.

Creating the graphical program may include creating a block diagram for the graphical program. The block diagram may be created in response to direct user input, e.g., the user may create the block diagram by placing or “dragging and dropping” icons or nodes on the display and interconnecting the nodes in a desired fashion. The plurality of nodes in the block diagram may be interconnected in response to user input to visually indicate functionality of the graphical program. The block diagram may have one or more of data flow, control flow, and/or execution flow representations.

Creating the graphical program may also include creating a graphical user interface or front panel, e.g., in response to user input. The graphical user interface may be created in any of various ways, e.g., depending on the graphical programming development environment used. Creating the graphical user interface or front panel may comprise specifying various user interface elements. For example, the user may specify the GUI by placing nodes in the block diagram, or by specifying GUI elements separately from the block diagram. These user interface elements may include elements such as one or more windows or panels, menu bars, context menus, etc., as well as various user interface controls and indicators for receiving program input and/or displaying program output. Examples of user interface controls and indicators include charts, graphs, push buttons, knobs, numeric controls, text boxes, list boxes, check boxes, etc.

In another embodiment, the graphical program may be programmatically generated rather than being manually created by a user. The above-incorporated patent application titled, “System and Method for Programmatically Generating a Graphical Program in Response to Program Information” discussed various examples of programmatically or automatically generating graphical programs.

In 303, the graphical program may be stored in a memory. For example, the graphical program may be stored in a memory of a computer system which executes a program to programmatically analyze/modify the graphical program, as described below. Storing the graphical program in the memory may include storing one or more data structures representing the graphical program in the memory and/or storing program instructions for the graphical program in the memory. The memory may be a memory of the same computer system which executes the program to programmatically analyze/modify the graphical program, or may be located elsewhere, e.g., in a different computer system or device.

In 305, the graphical program may be programmatically analyzed. In various embodiments, the graphical program may be a graphical program that performs any function for any application, and the graphical program may be analyzed to determine any information or characteristics regarding the graphical program. Several exemplary graphical program analyses are discussed below.

Programmatically analyzing the graphical program may include any technique or method implemented by a program that inspects or examines the graphical program. For example, programmatically analyzing the graphical program may include analyzing the one or more data structures and/or program instructions representing the graphical program in the memory, e.g., to determine graphical program elements (e.g., nodes, programmatic structures such as loops or case structures, user interface elements, connections, comments etc.) present in the graphical program and/or to determine a relationship among these graphical program elements.

In one embodiment, the user may select a desired criteria for the programmatic analysis. For example, the programmatic analysis may be performed to suggest modifications, or programmatically make modifications, to 1) improve performance of the graphical program, 2) correct errors in the graphical program, 3) update the graphical program, 4) reduce the footprint of the graphical program, 5) change the functionality of the graphical program to perform a user specified function, 6) modify the graphical program for a specific target (e.g., an embedded target or an FPGA) and/or 7) change the style of the graphical program's block diagram and/or graphical user interface. The above criteria may be displayed in a graphical user interface (GUI) for selection by the user. When the user selects the desired criteria, the program may then operate to programmatically analyze the graphical program in 305 according to this specified criteria and suggest changes (or programmatically make changes) conforming to this criteria. In one embodiment, the user may select a plurality of the above criteria for programmatic analysis. In one embodiment, regardless of criteria for programmatic analysis selected by the user, the programmatic analysis may by default indicate certain proposed changes, such as for improved performance or error correction.

In 307, one or more suggested modifications to the graphical program may be displayed. The one or more suggested modifications may be based on the analysis of the graphical program performed in 305. The suggested modifications which are displayed may depend on the purpose or reason for analyzing the graphical program. For example, in one embodiment, the goal may be to increase performance of the graphical program. Thus, in 305 the graphical program may be programmatically analyzed to determine information indicative of the graphical program's performance, and in 307 one or more suggestions for increasing the performance may be displayed based on this information.

In various embodiments, any of various aspects of the graphical program's performance may be programmatically analyzed, such as the graphical program's execution speed, execution determinism, input/output throughput, network communication throughput, etc. For example, the above-incorporated patent application titled, “Wizard for Programmatically Analyzing and Modifying Time-Critical Graphical Programs” describes a method for increasing the performance of a graphical program which performs one or more repetitive operations. Specifically, a method for eliminating time latency problems resulting from performing user interface functions within a time-critical graphical program is disclosed.

In another embodiment, the goal may be to modify functionality of the graphical program. For example, the graphical program may perform first functionality. It may be desirable to programmatically analyze the graphical program to determine one or more portions of graphical source code responsible for implementing this first functionality. In this case, one or more suggestions for changing the first functionality may be displayed. Also, as described below, in one embodiment the graphical program may be programmatically modified to perform second functionality instead of the first functionality.

In another embodiment, the goal may be to correct problems present in the graphical program. For example, the graphical program may be syntactically correct, but may have one or more semantic errors, e.g., as a result of improperly using one or more nodes in the graphical program in a way which is not intended or as a result of a particular combination of interconnected nodes which is invalid. Thus, a tool may be provided to the user to automatically analyze his graphical programs for such problems and display suggestions on how to modify the graphical programs.

As a related example, the graphical program may be developed or stored on a first computer system, and the user may desire to deploy the graphical program on a second computer system for execution, where the second computer system is a different type of computer system than the first computer system. For example, the first computer system may be a general purpose computer system, and the second computer system may be a target device such as an FPGA, a PDA, an embedded system in a device, etc. The graphical program may execute correctly on the first computer system but may include one or more portions of graphical source code which do not execute correctly on the second computer system, e.g., due to graphical program elements which are unsupported for the second computer system or due to semantic differences. Thus, a tool may be provided which is operable to automatically analyze the user's graphical program to determine such problems and display suggestions for modifying the graphical program (and possibly automatically modify the graphical program to fix the problems, as described below).

In another embodiment, the goal may be to update the graphical program. For example, the graphical program may be a graphical program that was created using an older version of a graphical programming development environment. This graphical program may not be compatible with a newer version of the graphical programming development environment. For example, the newer version may no longer support one or more of the graphical program nodes used in the graphical program, the semantics of one or more nodes may have changed in the newer version, the input/output parameters of one or more nodes may have changed, programming constructs used in the graphical program may have been superceded by new constructs, etc. Thus, a translator tool may be operable to analyze the original graphical program and display suggestions for modifying the graphical program to execute correctly under the newer version of the graphical programming development environment (and may possibly automatically update the graphical program, as described below).

As a related example, a tool may be operable to perform bug fixes or other updates to a graphical program. For example, one or more graphical programs may have been installed on the user's computer system as part of a software application installation procedure. The tool may be operable to analyze these graphical programs to periodically update their functionality or provide bug fixes. As another example, a graphical programming development environment may be operable to assist users by automatically (programmatically) generating various portions of graphical source code for inclusion in graphical programs. It may be desirable to provide a tool which analyzes existing graphical programs to determine such portions of automatically generated graphical source code in order to automatically update the graphical source code, similarly as described above. In one embodiment, a tool located on a remote computer system may be operable to remotely perform this programmatic analysis (and possibly programmatic modification also, as described below).

In another embodiment, the goal may be to perform a “search and replace” function for one or more graphical programs. For example, the user may specify a first graphical source code template and a second graphical source code template. A tool may programmatically analyze the graphical program(s) to find instances of the first graphical source code template and may optionally prompt the user to replace them with the second graphical source code template.

In another embodiment, the goal may be to modify the graphical program so that its execution can be distributed across multiple computer systems. As one example, it may be desirable to modify a graphical program so that the program executes on one computer system, and the graphical program's user interface is displayed on a second computer system. Thus a tool may programmatically analyze the graphical program to locate graphical source code related to user interface functionality and may programmatically modify the graphical program to communicate with the second computer system.

As noted above, displaying the one or more suggested modifications to the graphical program in 307 may be performed in any of various ways, e.g., depending on the particular reason for performing the analysis of the graphical program. In various embodiments, 307 may comprise displaying information of any kind. For example, in one embodiment, text information indicating the one or more suggested modifications may be displayed. In another embodiment, displaying the one or more suggested modifications to the graphical program may comprise visually altering an appearance of the graphical program to indicate the one or more suggested modifications. In another embodiment, displaying the one or more suggested modifications to the graphical program may comprise displaying one or more suggested portions of graphical source code to include in the graphical program. In addition to displaying suggested modifications to the block diagram or graphical source code of the graphical program, in one embodiment, one or more suggested modifications to a graphical user interface of the graphical program may be displayed. Suggested modifications may be highlighted, e.g., may have a different appearance or color, to visually indicate the suggested modifications.

In one embodiment, the suggested modifications may be not only displayed, but may also be automatically, i.e., programmatically applied to the graphical program. As shown in 309, in one embodiment, the user may be able to select which of the suggested modifications to automatically apply to the graphical program. User input selecting one or more of the suggested modifications to apply to the graphical program may be received. Various techniques may be used to prompt the user for this user input. For example, in one embodiment, the user may simply click a button or perform another action to request all the suggested modifications to be applied. In another embodiment, the user may be able to select a subset of the modifications to apply or may be prompted for a decision on whether to apply each modification one at a time.

In an alternative embodiment, the suggested modifications may be not displayed and/or the user may not be prompted to select which modifications to apply. Instead, the method may simply programmatically analyze the graphical program and programmatically modify the graphical program based on the analysis without interacting with the user as described above.

In 311, the graphical program may be programmatically modified to implement the one or more suggested modifications selected in 309. The graphical program may be programmatically modified with little or no input received during the modification process. In one embodiment, the method may include displaying a series of user interface panels or screens to guide the user through the process of modifying the graphical program or to allow the user to specify options affecting the modifications made to the graphical program. This series of screens may be referred to as a “wizard”.

In one embodiment, the graphical program may be programmatically analyzed to optimize graphical code during the build process (e.g., during creation of the graphical code). Thus, graphical code may be optimized in a manner similar to how a C compiler may optimize C code (e.g., “unrolling a loop”) during compilation.

It is noted that the above examples of reasons for programmatically analyzing graphical programs are intended to be exemplary only. The method described above may be utilized to programmatically analyze and/or modify a graphical program in any way and for any desired purpose or application.

FIGS. 5-8: Exemplary Graphical Programs

The remainder of the disclosure discusses one particular application of programmatic analysis and modification of a graphical program. In this application, it is desired to programmatically modify a time-critical graphical program to improve its performance by removing user interface functionality from the time-critical graphical program.

The time-critical graphical program may first be programmatically analyzed to determine graphical source code in the program involved with user interface functionality. In one embodiment, this may involve programmatically determining one or more user interface nodes present in the time-critical graphical program. Each user interface node may be operable to perform one of: a) displaying data in a user interface indicator from a source wire or b) providing data from a user interface control to a sink wire. For example, LabVIEW graphical programs can include user interface nodes (referred to as user interface terminals) to/from which wires can be connected from/to other nodes in the graphical program. For example, a wire may be connected from an output terminal of another node in the graphical program to a user interface node representing a user interface indicator on the graphical user interface. This wire may thus be referred to as a source wire, since it is a source of data displayed on the user interface. Similarly, a wire may be connected from a user interface node representing a user interface control on the graphical user interface to an input terminal of another node in the graphical program. This wire may thus be referred to as a sink wire, since it is a sink for data received from the user interface.

The time-critical graphical program may be then programmatically modified to instead exchange data with a second graphical program. The second graphical program may be programmatically generated as a part of the process of modifying the time-critical graphical program. The second graphical program may then perform the user interface functionality previously performed by the time-critical graphical program.

For example, where the unmodified time-critical graphical program previously generated data and displayed the data in a user interface indicator, the programmatically modified time-critical graphical program may instead pass the data to the second graphical program, and the second graphical program may display the data in the user interface indicator. Similarly, where the unmodified time-critical graphical program previously received data from a user interface control, the programmatically modified time-critical graphical program may instead receive the data from the second graphical program, which receives the data from the user interface control. Thus, the user's original graphical program may be automatically modified, and a second graphical program may be automatically generated, such that the performance of the real-time or time-critical application is increased.

FIG. 5 illustrates an exemplary time-critical graphical program created by a user. This example illustrates a simple graphical program for illustrative purposes only. As shown, the graphical program includes a while loop. The graphical source code inside the loop is performed for each loop iteration. In each iteration, first input data is received from a user interface control represented by the user interface node labeled, “Array”. Also, second input data is received from a user interface control represented by the user interface node labeled, “input2”. After some simple mathematical calculations performed on the input data, output data is provided to the user interface node labeled, “double precision float”, which represents a user interface indicator that displays the output data. Also, the current loop iteration number is provided to the user interface node labeled, “output1”, which represents a user interface indicator that displays the current iteration number.

FIG. 6 illustrates the time-critical graphical program after being automatically modified as described above. As shown, the time-critical graphical program no longer performs a user interface function. The user interface nodes have been programmatically replaced with data read and data write nodes (RT FIFO nodes) as described above.

FIG. 7 illustrates a programmatically generated data exchange program that accompanies the modified time-critical graphical program. The data exchange graphical program includes a communication loop. Within the communication loop, two data read nodes corresponding to the two data write nodes in the time-critical graphical program have been included. Also, two data write nodes corresponding to the two data read nodes in the time-critical graphical program have been included. The TCP node on the left side of the graphical program is operable to receive data sent from a UI graphical program. The TCP node on the right side of the graphical program is operable to send data to the UI graphical program.

FIG. 8 illustrates a programmatically generated UI program that accompanies the data exchange graphical program. The UI graphical program includes two user interface nodes representing the two user interface indicators used in the original time-critical graphical program. These user interface nodes are labeled identically, i.e., “double precision float” and “output1”. Similarly, the UI graphical program includes two user interface nodes representing the two user interface controls used in the original time-critical graphical program. These user interface nodes are labeled identically, i.e., “Array” and “input2”. The user interface nodes representing user interface controls have been placed inside of a loop where they can be read continuously. On the other hand, the user interface nodes representing user interface indicators may not need to be inside the loop, as shown.

For further details regarding this example, please refer to the above-incorporated patent application titled, “Wizard for Programmatically Analyzing and Modifying Time-Critical Graphical Programs”.

Although the embodiments above have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications. 

1. A computer readable memory medium that stores program instructions for programmatically analyzing a graphical program, wherein the program instructions are executable by a processor to implement: automatically analyzing the graphical program, wherein the graphical program comprises a plurality of nodes and connections between the nodes, wherein the plurality of interconnected nodes visually indicate functionality of the program, and wherein said automatically analyzing the graphical program comprises automatically analyzing the plurality of nodes and the connections between the nodes; and automatically modifying the graphical program based on said automatically analyzing the graphical program, wherein the one or more suggested modifications are selected from the following set of: displaying a new node; removing a node; displaying a new connection; modifying a connection; and removing a connection.
 2. The memory medium of claim 1, wherein said automatically modifying the graphical program comprises one or more of: improving performance of the graphical program; correcting an error in the graphical program; or changing functionality of the graphical program.
 3. The memory medium of claim 1, wherein the graphical program comprises a graphical data flow program.
 4. The memory medium of claim 1, wherein said automatically modifying the graphical program comprises automatically modifying the graphical program with no user input received during said modifying.
 5. The memory medium of claim 1, wherein the program instructions are further executable to implement: displaying one or more suggested modifications to the graphical program based on said automatically analyzing the graphical program; and receiving user input requesting to perform the one or more suggested modifications; wherein said automatically modifying the graphical program comprises automatically performing the one or more suggested modifications.
 6. The memory medium of claim 1, wherein the program instructions are further executable to implement: displaying one or more options for affecting the programmatic modification of the graphical program; receiving user input selecting one or more of the one or more displayed options; wherein said automatically modifying the graphical program comprises automatically modifying the graphical program in accordance with the one or more selected options.
 7. The memory medium of claim 1, wherein the graphical program includes a graphical user interface; wherein said automatically analyzing the graphical program comprises automatically analyzing the graphical user interface; and wherein said automatically modifying the graphical program comprises automatically modifying the graphical user interface.
 8. The memory medium of claim 1, wherein said automatically modifying the graphical program includes automatically replacing a first node in the graphical program with a second node.
 9. The memory medium of claim 1, wherein said automatically modifying the graphical program includes automatically changing one or more properties of at least one of the plurality of nodes.
 10. The memory medium of claim 1, wherein the graphical program has first functionality; wherein said automatically modifying the graphical program includes automatically modifying the graphical program to have second functionality, wherein the second functionality is different than the first functionality.
 11. The memory medium of claim 1, wherein the memory medium stores the graphical program.
 12. A computer-implemented method for automatically modifying a graphical program, the method comprising: storing the graphical program in a memory, wherein the graphical program comprises a plurality of nodes and connections between the nodes, wherein the plurality of interconnected nodes visually indicate functionality of the program; automatically analyzing the graphical program, wherein said automatically analyzing the graphical program comprises automatically analyzing the plurality of nodes and the connections between the nodes; and automatically modifying the graphical program based on said automatically analyzing the graphical program, wherein said automatically modifying the graphical program comprises modifying at least one node and/or connection of the plurality of interconnected nodes which visually alter an appearance of the graphical program, wherein the one or more suggested modifications are selected from the following set of: displaying a new node; removing a node; displaying a new connection; modifying a connection; or and removing a connection.
 13. The method of claim 12, wherein said automatically modifying the graphical program comprises one or more of: improving performance of the graphical program; correcting an error in the graphical program; or changing functionality of the graphical program.
 14. The method of claim 12, wherein the graphical program comprises a graphical data flow program.
 15. The method of claim 12, wherein said automatically modifying the graphical program comprises automatically modifying the graphical program with no user input received during said modifying.
 16. The method of claim 12, further comprising: displaying one or more suggested modifications to the graphical program based on said automatically analyzing the graphical program; and receiving user input requesting to perform the one or more suggested modifications; wherein said automatically modifying the graphical program comprises automatically performing the one or more suggested modifications.
 17. The method of claim 12, further comprising: displaying one or more options for affecting the programmatic modification of the graphical program; receiving user input selecting one or more of the one or more displayed options; wherein said automatically modifying the graphical program comprises automatically modifying the graphical program in accordance with the one or more selected options.
 18. The method of claim 12, wherein the graphical program includes a graphical user interface; wherein said automatically analyzing the graphical program comprises automatically analyzing the graphical user interface; and wherein said automatically modifying the graphical program comprises automatically modifying the graphical user interface.
 19. The method of claim 12, wherein said automatically modifying the graphical program includes automatically changing one or more properties of at least one of the plurality of nodes.
 20. The method of claim 12, wherein the graphical program has first functionality; wherein said automatically modifying the graphical program includes automatically modifying the graphical program to have second functionality, wherein said second functionality is different than said first functionality. 